In the development of electronic circuitry, state diagrams and corresponding state machines are sometimes utilized to describe and to implement logical functions.
By appropriate manipulation of logical functions described by the state diagram, a state machine implementation, using, e.g. logical gates, can be effectuated. The state machine so-formed is operably responsive to the application of input signals thereto to generate outputs corresponding to the logical functions which the state machine implements. Because the state machine implementation is a hardware implementation of a logical function, the state machine implementation permits the quick execution of the logical functions as well as providing, generally, circuitry of high reliability.
In some state machines, the same sequence of states is performed at different locations of the state machine. Particularly when the state machine implements a lengthy series of logical functions, the same sequence of states might need to be performed at a plurality of different locations of the state machine. For instance, in a state machine which implements a bridge interfacing computer buses of a computer system, a lengthy series of logical functions are typically required to be implemented. Groups of sequences of states are performed at different locations of the state machine.
In a conventional, sequential state machine, such same sequence of states are merely repetitiously repeated in the hardware construction of the state machine, and the resultant state machine merely sequences through the states, in conventional manner.
However, because of the repetition of the same state sequences, there is a duplication of circuitry at the locations of the state machine whereat the same sequences of states are repeated. If a manner could be provided by which to reduce the level of repetition of the same sequences of states of the state machine, the size of the circuitry required to implement the state machine could be reduced.
It is in light of this background information related to state machines that the significant improvements of the present invention have evolved.